Question 109890
3x+6y=0
x= 2/3 
:
Just substitute 2/3 for x in the 1st equation, and find y
:
3({{{2/3}}}) + 6y =0
:
The 3's cancel and you have;
2 + 6y = 0
6y = -2
y = {{{-2/6}}}
y = {{{-1/3}}}
:
:
Check solution in the original equation:
3({{{2/3}}}) + 6({{{-1/3}}}) = 0
 2 - 2 = 0